i'm not sure how the database for Perl Monks is set up, but
i suspect that this is not a simple addition. unless every
node stores the id of its top-level parent node (in addition
to the id of its immediate parent), then multiple SQL
queries would need to be made to traverse the tree of
children and get a reply count.

this could be entirely incorrect, but i suspect vroom
would have added this feature if it weren't near impossible
to do easily in SQL.

On the contrary, it's already been done everywhere else on the site. The Monastery Gates shows the number of replies along with each message, as does each individual section. Recursive replies wouldn't need to be counted, only top level. I only suggest adding that functionality to the Newest Nodes page.

OK. i think it's basically useless to only count top-level
replies, since the purpose of showing the count is
presumably to be able to compare it with an earlier value
and thus notice additions to a thread easier without having
to correlate and count the appropriate comments in the
Notes/Replies.